15 April 2009 was the last full day of GOES-13 imagery — the satellite was placed back into on-orbit storage on the morning of 16 April. GOES-13 had been brought out of storage during the Summer of 2008, to act as “GOES Central” (at 105Âº West longitude) and provide imagery through the Fall eclipse period. Larger on-board batteries allow GOES-13 to make imagery available during eclipse periods (when the satellite is in the Earth’s shadow, and the solar panels cannot provide the power necessary to operate the instruments) –Â but other improvements to GOES-13 include better image-to-image navigation, and the 4-km resolution water vapor channel that debuted on GOES-12.

The 4-km resolution GOES-13 6.5 Âµm water vapor imagery (above) displayed widespread mountain wave signatures across much of the western US on 15 April — and many of the smaller-scale areas of mountain waves were unable to be resolved using the 8-km resolution GOES-11 6.7 Âµm water vapor imagery (below).

8-km resolution GOES-11 6.7 Âµm water vapor images

Such mountain wave signatures are often a good indicator of the likelihood of turbulence — and there were indeed a large number of pilot reports (PIREPS) of turbulence (including at least 11 reports of severe turbulence) across much of the western US, as seen on AWIPS images of the GOES-11/GOES-12 water vapor channel data (below).